The present invention concerns a method of checking the existence of a correct end position of an electromagnetically actuated gas injector arranged in an internal combustion engine between a fuel source and a combustion chamber.
The invention further concerns an internal combustion engine having an engine control, a source for gaseous fuel, at least one combustion chamber in which the gaseous fuel is ignited, and an electromagnetically actuated gas injector arranged between the source for the gaseous fuel and the at least one combustion chamber.
Electromagnetically actuated gas injectors are movable from a closed end position in which they interrupt the connection between the fuel source and the combustion chamber into an opened end position by the application of a suitable electric opening voltage and the opening current flowing as a result. The return movement of the gas injectors into the closed end position is preferably effected mechanically by a spring in the injector.
If the gas injector is not completely closed due to a defect or because of a foreign body gaseous fuel (hereinafter referred to for brevity as ‘gas’) can flow through the gas injector at an unwanted moment in time and/or in an unwanted amount. An ignitable mixture can be formed at a moment in time which is not intended for that, from the gas flowing into the combustion chamber and mixing there with air. In addition this can involve a lower lambda value of the mixture in the combustion chamber than is wanted (excessively rich mixture) as more gas flows into the combustion chamber than is wanted. In both cases damage to the internal combustion engine can occur due to unwanted or uncontrolled combustion.
Various methods are already known, which detect whether the gas injector is in its opened end position. If the gas injector is in its opened end position at the checking time, although it should be planned to be closed at that time, it is possible in that situation to conclude that there is a defective gas injector.
A disadvantage with such methods is that at least one combustion cycle takes place between the occurrence of the defective injector position and detection of that condition.